Doc's ULTIMATE TORQUE ARMS fit most of the frame UPDATE 2013

[Doctorbass]

UPDATE: 2014 keep same revision

After many request i decided to review the actual desing rev 4 and add some features.

The new design is lighter, easier to glue or put screw and is still more than strong enough.

I have got many request to add some holes for those who don’t have any quality drill kit and for the lycra type bike that every gram of saved weight count and I acceped to include some holes in strategic area where it don’t really affect the required strength.

In other words, with a pair of these great T-A, your axel will still be by far the weakest part!

For the lasts batch I made these great T-A it was a real pain to rework them for the threaded hole and to continue to supply these great T-A and mot being tired of that rework job, I decided to save me some pain and to ask my supplier to finally make them for me.

The cost they charge me raised by 7$ so the new price is now 36$ per set. But this is still cheaper than any pair of torque arms on the market. I also made a bigger batch of 75 set instead of 50 to help keep the cost as low as possible with these new features.

These new revision 5 will certainly be appreciated and should satisfy more people.

The new batch should arrive the next week so all peoples that reserved their set will be informed about this update by PM

Doc

[e-biker]

Doc I will take a set of those new style torque arms, just let me know when you are ready.

[el_walto]

I wonder if REV 4 will have an even stronger glue bond because some of the glue can fill the holes? Or maybe i'm wrong and it's all about flat surface area.

[Doctorbass]

I wonder if REV 4 will have an even stronger glue bond because some of the glue can fill the holes? Or maybe i'm wrong and it's all about flat surface area.

These holes are the best trade off for people that want to fix them with screw or epoxy or weld. These holes will allow people to add epoxy AND screw or steel wire added with epoxy et any combinaison of these. There is a bit less direct parallel surface as well but these holes also help to better fill the volume between non totally flat frame and the T-A.
They also add some grip.

If the epoxy is applied properly, you will twist your axel way before they unbond !
I am pretty confident with this new design

Doc

[Microbatman]

Great work!!
Agree with making them with holes. Great idea. Holes=lighter and more flexibility without sacrificing strength.
What size are the holes?

[mikebikerad]

Next revision you will have to make some titanium versions! The holes will definitely make life easier. What type of drill bits does the machine shop use on these? AlTiN?

[Doctorbass]

The holes to lighten the T-A are 8mm. This is the smallest size they can make in that hard steel type. The hole on threaded hole for the right side T-A is 9mm and the tap is 10.0mm x 1.0mm
This kind of steel require particular technique for laser cut. It is very hard to cut with the laser or waterjet. With smaller holes than 8mm, they would need to crank up the laser power too much and metal would melt too much before finishing the cut due to the temp increase.

About the drill bit they use i dont know wich type. i will ask.

When i drilled the holes in the last batchs, i had to rework the drill bit edges to every 3-4 T-A set !!! and believe me i know how to drill and calculate drill speed, use coolant etc... but this metal is so hard than even a 25$ drill bit dont last for more than 3-4 T-A set !

Doc

[howbeit]

For those of us planning to use these torque arms on a front fork, would it be better to just get two left TAs?

[Doctorbass]

For those of us planning to use these torque arms on a front fork, would it be better to just get two left TAs?

Or to cut the leg on the right T-A with a grinder

Take about 1 minute and 0.10$ of grinder 1/8" blade, that's all

Doc

[el_walto]

For those of us planning to use these torque arms on a front fork, would it be better to just get two left TAs?

Has there been much success with mounting these on front forks? They may fit some ridged ones, but i can't see them fitting any suspension forks.

[Doctorbass]

For those of us planning to use these torque arms on a front fork, would it be better to just get two left TAs?

Has there been much success with mounting these on front forks? They may fit some ridged ones, but i can't see them fitting any suspension forks.

If you use the grinder to remove some material and then bond it with the DP420, it work for few forks. At least some peoples tried and had succed.

there is few post about that

Doc

[Merlin]

hello,

when they are so strong why these Torque arms are 10mm deep?
i think 5mm will be enough...would look nicer i think?!
(like working tools for bolt / nut)

let me know if iam wrong.

regards from germany,

[sardini]

hello,

when they are so strong why these Torque arms are 10mm deep?
i think 5mm will be enough...would look nicer i think?!
(like working tools for bolt / nut)

let me know if iam wrong.

regards from germany,

The axle will slip....

[Merlin]

really?
before doc built this ultimate arms, what did you use before? i can follow when you have a 10KW Monster...but 2-3-4Kw?!

i bet you will be right that before the mega torque arm will slip the axle will do.

a normal DIN wrench 19mm is 8mm deep (a2) 250mm long (L)



a normal wrench is for ~380NM (!)

take a 1meter pipe and see what happened to a extrem 12.9 bolt. the Bolt will break.
look at your wrench.....yap theres nothing...

nobody have to missunderstand me...i like this extrem stuff.
just wondering and curious of the real torque/NM/Physics stuff

[Doctorbass]

really?
before doc built this ultimate arms, what did you use before? i can follow when you have a 10KW Monster...but 2-3-4Kw?!

i bet you will be right that before the mega torque arm will slip the axle will do.

a normal DIN wrench 19mm is 8mm deep (a2) 250mm long (L)



a normal wrench is for ~380NM (!)

take a 1meter pipe and see what happened to a extrem 12.9 bolt. the Bolt will break.
look at your wrench.....yap theres nothing...

nobody have to missunderstand me...i like this extrem stuff.
just wondering and curious of the real torque/NM/Physics stuff

Hi and welcome on E-S
hre is my physics:

more than 350 T-A set sold... and NONE of these ever break... THAT'S MY PHYSICS

What you forget about your math is the strengh of the chineese steel axel.... they require to lower the PSI.. wich mean they require more surface to share a pressure that is lower of the efges of the axel flat.. .that's why i have chose about 10mm thickness ( 3/8")

In other words, you could have a 1/16" thick torque arm from the most strong unknown material ever ... that just can't break.. but the problem woujd not be the T-A but the axel itself.. .It would break and strip the flat area....

By increasing the surface of contact you reduce the force per unit of surface ( pressure).

Doc

[gensem]

+1 Doc...

My new dropouts are 20mm thick because now im going to use a big hubmotor.

[Doctorbass]

GOOD NEWS!

NEW BATCH REV 5 ARRIVED !!!

By the end of this weekend i should will have finished making the threads on the 75 set and have the preordered set ready to ship That Craftman drill really draw peak of 65Amp at 15Vdc when i make the threads !! Motor is still alive after 350 set drilled with Your Doc just dont overpower hub motor, but the drill too !

I know the wait have been so long for some but i ensure you it worth!

They are now about 75 gram less and still really strong.

All person that preordered some will be contacted by PM. Other no worrie, there is still about half of the batch availlable
They should be ready to ship by the end of this weekend. i'm doing my best but i have Discovery Channel coming here on Wednesday to make some shoot in my garage about my hobby so i have some cleaning and preparations in the schedule

36$ per set
(one set = one pacman and one with longer leg)


Some pictures for you

Doc

[Doctorbass]

Some more:

For relative comparaison i have included the weight measurement of a standard X5 hub motor axel wich is about 2.5 time heavier than the 2 T-A together

Doc

[space4dreamz]

Hi Doc

I bought from you a pair of V4 which I enjoy.

But I'm curious - why bother about 75g when I've already got about 100's times this weight on my rear axle? does it have any other significance?

[Doctorbass]

Hi Doc

I bought from you a pair of V4 which I enjoy.

But I'm curious - why bother about 75g when I've already got about 100's times this weight on my rear axle? does it have any other significance?

Hi,

The added hole aer not only for weight, but for easy acces for bolt or better glue grip or for welding. Sometime it also save some money on the international shipping due to teh category of weight they are.

but yes.. i had some request for having them with less weight.. maybe some lycra with kW lightweight motors

Doc

[Microbatman]

They look great!
Can't wait to install them on my new build.
A definite must have for any hub motor install. Glad you made and brought this product to market.

[alex12342011]

PM Sent, ready to buy just waiting for reply.

[electr0n]

Me too. PM Sent. One question why didn't you make these pinching? What type of glue to use?

[Alastor]

Great work Doc i really like em just because they weight less they look awesome as well

[Doctorbass]

before ordering can you post pictures of them installed on the bike

and are they holding with DP420 only?

Search in that thread there is already couples of pictures of that

Yes they can hold perfectly only with the DP-420. .. and ... at any power, if they are properly bonded, your stator axel will twist way before the T-A could unstick!

Doc